Recovery of Virus Morphologically Identical with Psittacosis from Thiamin-Deficient Pigeons

A virus closely related to, if not identical with that of psittacosis was isolated from about 5% of 400 pigeons on a thiamin-deficient diet. The observations made suggest: 1. That pigeons should be added to the list of birds naturally infected with psittacosis virus and therefore of possible importance in the epidemiology of the disease, and 2. That thiamin deficiency may be capable of changing a latent infection with psittacosis virus into an active stage, with consequent danger of spread to other birds and to man.